On February 13 and 14, 1945, three successive waves of British and U.S. aircraft rained down thousands of tons of high explosive and incendiary bombs on the largely undefended German city of Dresden. Night and day, Dresden was engulfed in a vast sea of flame, a firestorm that generated 1,500-degree temperatures and hurricane-force winds. Thousands suffocated in underground shelters where they had fled to escape the inferno above.